中文摘要：

目的探讨人间充质干细胞（MSCs）对放射诱导后BV2小胶质细胞中Toll样受体（TLR）信号通路的影响。方法常规培养MSCs及BV2小胶质细胞。实验分为BV2空白对照组、BV2联合MSCs处理组、单纯照射组及BV2照射联合MSCs处理组。BV2细胞放射剂量为单次照射106y。采用实时荧光定量PCR检测细胞白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、Toll样受体2（TLR2）、Toll样受体4（TLR4）的表达，同时采用酶联免疫吸附测定（ELISA）法检测细胞上清中IL-6和TNF-α的表达。结果实时荧光定量PCR结果显示，单纯照射组细胞IL-6及TNF-α含量较空白对照组明显升高，RV2照射联合MSCs处理组IL-6及TNF—α含量较单纯照射组组细胞明显降低，差异均有统计学意义（P〈0．05）。ELISA实验结果与PCR结果类似。此外，实时荧光定量PCR结果显示，间充质干细胞可下调放射后BV2细胞中TLR2和TLR4的表达。结论MSCs可通过减少TLR信号通路相关因子的释放，抑制放射所致的小胶质细胞炎症反应。

英文摘要：

Objective To investigate the effect of human mesenchymal stem cells （MSCs） on changes of tolMike receptor （TLR） signal pathway in BV2 microglial cells caused by radiation. Methods Human MSCs and BV2 microglial cells were cultured routinely. The experiment included four groups （un-irradiated BV2 control group, un-irradiated BV2 plus MSCs treatment group, irradiated BV2 group, irradiated BV2 plus MSCs treatment group）. A single dose of 10 Gy was given to BV2 cells. BV-2 and MSCs co-culture experiments were performed through Transwell co-culture system with MSCs （105 per upper insert） and BV2 （2×10^5 per lower well）. Quantitative real-time PCR （qRT-PCR） was applied for investigating the mRNA expressions of interleukin （IL）-6, tumor necrosis factor （TNF）-α, TLR2 and TLR4. ELISA kits were used to measure the protein expressions of IL-6 and TNF-cc Results The qRT-PCR showed that the IL-6 and TNF-α mRNA expressions in the irradiated BV2 group were significantly increased as compared with those in the un-irradiated BV2 control group （P〈0.05）; the IL-6 and TNF-α mRNA expressions in the irradiated BV2 group were significantly increased as compared with those in the irradiated BV2 plus MSCs treatment group （P〈0.05）; ELISA indicated similar results. The qRT-PCR results suggested that MSCs could decrease the TLR4 and TLR2 mRNA expressions in the irradiated BV2 cells. Conclusion MSCs can mitigate the inflammatory response in microglial cells induced by radiation through modulating the related factors in TLR signal pathway.